Psoriasis is an inherited, chronic, proliferative disease characterized by epidermal hyperplasia and inflammation. The disease is characterized by the presence of psoriatic lesions that appear as erythematous, circumscribed plaques covered by loosely adherent silvery scales. The lesions may become extensive and may involve any area of the body, although lesions most often appear on the elbows, knees and scalp. Although the psoriatic plaques usually remain localized, in some cases the disease is sufficiently widespread as to be incapacitating and may be prolonged and unpredictable. Although many treatments for psoriasis provide limited relief, a common treatment for psoriasis involves topical application of corticosteroids, sometimes with occlusive dressings. However, the benefits of such treatments must be balanced against their adverse effects which can include skin atrophy with telangiectasia and striae formation as well as adrenal suppression.
An extremely effective treatment for moderate to severe psoriasis involves topical application of a compound called anthralin (1, 8-dihydroxyanthrone). Beneficially, anthralin has no substantiated systemic toxic or carcinogenic effects and provides a more prolonged remission than is usually evidenced by topical corticosteroids. Anthralin is usually incorporated into cream or ointment dosage forms for skin application at concentrations ranging from 0.1 percent to about 8 percent. The therapeutic effects of anthralin appear to require only a short contact with the psoriatic lesions and may be applied daily for periods of 15 to 60 minutes and then washed off with soap and water. Unfortunately, anthralin is not widely used because of its ability to irritate the perilesional skin and its tendency to stain the hair, skin and nails of the patient, as well as any fabrics or bathroom fixtures that come in contact with the anthralin composition. The resultant staining leaves a deep violaceous color and these side effects have reduced the acceptance of this treatment.
Accordingly, it is an object of the present invention to provide a lenitive composition for application to the skin of an anthralin patient for reducing anthralin-induced inflammation and the staining associated with anthralin use. Included in this object is the provision for a composition for reducing the staining of skin, hair and nails and the skin irritation associated with anthralin treatment of psoriasis. A further advantage of the composition and method of the present invention is the provision for reducing or preventing the staining of fabrics, particularly pajamas and bedclothes, as well as bathroom fixtures as a result of anthralin treatment of psoriasis.
A further object of the present invention is to provide a lenitive composition of the type described that can be applied as a single phase aqueous treating solution that can be easily applied and removed from the effected areas of the skin.
It has been reported by Ramsay et al that anthralin-induced inflammation may be reduced by the application of certain organic amines. J. Am. Acad. Dermatol. 1990, Vol. 22, pages 765-772 and Vol. 23, pages 73-76. In those publications, it is noted that while anthralin therapy is effective even with short contact, inflammation of the perilesional skin is a problem. Accordingly, dilute potassium hydroxide has been used to deactivate the anthralin and has led to a reduction in anthralin-induced inflammation, but not in its therapeutic effect. Because potassium hydroxide is also an irritant, the publications evaluated the use of certain organic amines, namely alkylamines and alkanolamines for a similar inhibitory effect on anthralin-induced inflammation. The amines were used as solutions dissolved in dichloromethane. However, dichloromethane is used in cleaning fluids and its human toxicity is known to be narcotic in high concentrations. Additionally, triethanolamine was used in an emulsion at an amine concentration of 10 percent by weight. However, the residual effect of the emulsion on the skin of the patients hampers the therapeutic action of subsequent anthralin treatments.
Accordingly, it is another object of the present invention to provide a new and improved lenitive composition containing the effective organic amines and a film former in an aqueous non-toxic and dermatologically acceptable carrier.
Other objects, features and advantages will be in part obvious and in part pointed out more in detail hereinafter.
These and related objects are achieved in accordance with the present invention by providing a lenitive composition for application to the skin of an anthralin-treated patient for reducing anthralin-induced inflammation and the staining associated with anthralin use comprising a single phase aqueous treating solution comprising an organic amine and a film-forming agent dissolved within a nontoxic dermatologically acceptable carrier. The organic amine is selected from the group consisting of lower alkyl and lower alkanol primary, secondary and tertiary amines and comprises about 1-25 percent by weight of the single phase aqueous treating solution. The solution is topically applied to the anthralin-treated areas so as to completely cover the treated areas. The solution is applied after anthralin wash off and is permitted to dry, but can also be applied before wash off as well, preferably in the form of a fine spray or mist.
A better understanding of the objects and advantages of the invention will be obtained from the following detailed description which sets forth an illustrative embodiment and is indicative of the way in which the principles of the invention are employed, including the several steps of the method and the relation of one or more of such steps with respect to each of the others and the composition possessing the features, characteristics, properties and relation of elements described and exemplified herein.